HOA Board member billing inappropriate expenses to the HOA

For the second time this year, a member of our HOA Board has submitted expenses for items that were contrary to responsibilities for the HOA. For the first expenditure, the Board admonished the member and included an explanation of why. For the second expenditure, the member will be asked, with the approval of the other Board members, to return the monies to the HOA.

Based on my four-year history on the Board with this member, they will undoubtedly refuse to return the monies. A motion will then be entertained to excuse the person from office, without cause (our Bylaws permit this), for the remainder of their term, which is at the end of this month.

I have reviewed Robert’s Rules and have not found an answer to this question. How can we prevent this person from nominating themselves at the election next month and not allow them on the ballot for at least one year?